The present invention relates generally to communication networks, and more particularly to methods and apparatuses that provide dynamic error correction for streamed media over wired and/or wireless connections/networks.
The Internet and other similar networks are currently being used to deliver streaming media from a server device to a client device. For example, audio and/or video content from news broadcasts can be streamed, from a server device/devices, through a network to one or more client devices.
The terms xe2x80x9cstreaming mediaxe2x80x9d and xe2x80x9cstreamed mediaxe2x80x9d, as used herein, essentially mean real-time or near-real-time delivery of critical content (e.g., audio and/or video data) to a subscribing user""s client device or devices. The client device/devices render the streamed media in a way that is appropriate for the client device and the media. By way of example, a live or previously recorded radio program can be transmitted as streamed audio data over a network to a wireless communication device, such as, e.g., a mobile telephone device, which then reproduces the audio signal.
To provide better service to the user, some networks that are used for streaming media are beginning to offer predictable levels of service. For example, in certain networks, an attempt is made to maintain both the throughput of the network connections (i.e., the data rate) and the errors introduced into data transmitted on those connections (i.e., the residual bit error rate or BER) within certain predicted limits, for the duration of a connection.
An example of such a network is the so-called xe2x80x9cthird generationxe2x80x9d (3G) wireless network. 3G wireless networks are being designed to support high data rate wireless telephone services. Streaming content services are predicted to be major applications in these and other types of networks. Such services will be required to deal with certain levels of BER while maintaining an acceptable streaming content experience for subscribing users. As such, in many of these networks there is a need for error correction services that reduce the amount of corrupted data.
U.S. Pat. No. 6,141,788, issued to Rosenberg et al., provides a method for applying forward error correction (FEC) techniques in packet networks. FEC, which is a well-known error correction technique, provides a mechanism by which a sending device provides a receiving device with additional FEC data that can be subsequently used by the receiving device to detect and correct errors in received data. Thus, to support FEC the sending device typically includes an FEC encoder and the receiving device typically includes an FEC decoder. FEC allows for different levels of encoding. The different levels of encoding can be expressed by a density ratio based on the amount of FEC data generated for a given amount of data. Thus, for example, in certain systems the FEC encoding level may be xe2x80x9chighxe2x80x9d when there is a ratio of one FEC packet for every data packet. In other systems, the FEC encoding level may be xe2x80x9clowerxe2x80x9d such that there is a ratio of one FEC packet for every four data packets.
Rosenberg et al. disclose a method by which FEC packets may be forwarded from a sending device to one or more receiving devices. The receiving devices may or may not be configured to provide FEC decoding. For those receiving devices that can provide the requisite FEC decoding, Rosenberg et al., provide a way for the decoder to identify the level of FEC encoding from the header of an FEC packet, and thereafter complete the error correction process, as needed.
One of the drawbacks to the methods and apparatuses provided by Rosenberg et al., is that the sending device controls the level of FEC encoding independent of the receiving device(s). The receiving device(s) is simply advised as to the level of FEC encoding has been applied by the sending device. The receiving device is unable to influence the sending device""s selection of the FEC encoding level.
It would be advantageous for a receiving device to be able to influence the sending device""s decision, such that, for example, the receiving device can better adapt the density of error correction applied for a given location/time. Thus, there is a need for improved methods and apparatuses that allow a receiving device to control the level of encoding applied to streamed media by a sending device.
In accordance with certain aspects of the present invention, methods and apparatuses are provided which allow a receiving device to dynamically control and/or otherwise influence a sending device""s decision regarding the level of error correction that is applied to streamed media.
For example, in accordance with certain exemplary implementations of the present invention, a method is provided for use in a receiving device. The method includes generating a request for streamed media having an initial requested level of error correction provided therein. In this manner, the receiving device is allowed to request that a sending device provide a particular level of encoding for the streamed media. Moreover, in certain implementations, the method further includes having the receiving device dynamically modify the requested level of error correction applied to the streaming media.